Diagnostic connector assembly (DCA) interface unit (DIU)

ABSTRACT

In a diagnostics system for use on vehicles, wherein the improvement comprises a connector assembly that translates diagnostic connector assembly signals into a digital format suitable for computer based analysis and fault diagnosis on an individual vehicle and vehicle fleet basis.

RELATED APPLICATIONS

This Application claims rights under 35 USC §119(e) from U.S.Application Ser. No. 61/154,588 filed Feb. 23, 2009, the contents ofwhich are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to embedded vehicle diagnostic systems andmore particularly to interface units supporting embedded diagnostics forexisting analog diagnostic connector assemblies.

BACKGROUND OF THE INVENTION

In the past, diagnostic connector assemblies (DCAs) have been built intolegacy military vehicles typically for associated analog sensormeasurements from the engine or transmission. These diagnosticconnectors were used in conjunction with specialized test equipment, inwhich the test equipment was typically brought out to a vehicle after aproblem was encountered. When not in use, the diagnostic connectorassembly is protected by a dust cover. This concept of operation doesnot provide constant, real time monitoring because the test equipmenthad to be moved up to a vehicle each time testing was required. Thisincreases the logistical footprint because of added test equipment formaintainer to bring forward, as well as test equipment to be maintainedover the extended life cycle of the platform. Significantly, the specialtest equipment used in the past was only effective after a failurebecause on board vehicle health was not continually monitored.

A significant number of about 200,000 or more of the older legacymilitary vehicle fleet have analog diagnostic connector assemblyconnectors for troubleshooting older engines and transmissions. Use ofthese connectors in troubleshooting requires specialized test equipmentand experienced personnel provided with detailed technical instructions.Support of the specialized test equipment and personnel trainingincreases cost of the support function and increased the logisticsfootprint.

Condition Based Maintenance (CBM+) concepts are now regularly deployedthat require digitally formatted data for vehicle and fleet healthmonitoring and fault isolation, and that there is a desire and need tolower legacy vehicle total ownership costs.

By way of further background, for older analog military vehicles it wasimportant to be able to perform diagnostic testing on their combustionengines and transmissions. In order to do this these vehicles wereprovided with a diagnostic connector assembly which was simply aconnector to connect analog signals on a vehicle bus to test equipmentthat was pulled up to perform the diagnostic function. It is noted thatin these legacy vehicles there was nothing embedded in the vehicle tosupport diagnostics.

Moreover, the future requires taking advantage of signals and pin outsin which signals that are measured are measured for both the combustionengine and the transmission. It is therefore important that a diagnosticinterface unit apply a new technology mount to the diagnostic connectorassembly and the vehicle, stay on the vehicle and therefore be embedded,and provide a microprocessor such that diagnostic inferences can be madewith respect to the vehicle. Additionally, it would be important thatdiagnostic expertise be installed within the module, with theprogramming providing the module with an understanding of thephenomenology associated with for instance, both the engine and thetransmission, thus to be able to develop diagnostic conclusions fordetection and isolation of faults; and to be able to do this at thevehicle.

A need exists, therefore, for a diagnostic connector assembly interfaceunit that avoids the above disadvantages and allows for digitallyformatted data for vehicle and fleet maintenance and lower legacyvehicle total ownership costs.

Note, telenostic systems are described in the following U.S. PatentApplications, filed on even date herewith, assigned to the assigneehereof and incorporated herein by reference: Ser. No. ______ (docketnumber BAEP 1141) In Service Support Center and Method of Operation,Ser. No. ______ (docket number BAEP 1159) Telenostics, Ser. No. ______(docket number BAEP 1160) Portable Performance Support Device and Methodfor Use, Ser. No. ______ (docket number BAEP 1161) TelenosticsPerformance Logic, and Ser. No. ______ (docket number BAEP 1162)Telenostics Certify.

SUMMARY OF INVENTION

In order to solve the above problems a low cost connector assembly ormodule is provided that translates the analog diagnostic connectorassembly signals into a digital format suitable for computer basedanalysis and fault diagnosis on an individual vehicle and on a vehiclefleet basis. The module discussed above is referred to herein as adiagnostic interface unit or DIU.

The subject diagnostic interface unit in one embodiment can take theoutput of a legacy diagnostic connector assembly and modify it orinterface it. In another embodiment, it is the purpose of the diagnosticinterface unit to interface to the older vehicles that have only thediagnostic connector and provide an embedded diagnostics capabilitywhere none had previously been embedded in the vehicle.

In the embodiments to be described the diagnostic interface unit plugsinto the analog connectors used on legacy vehicles that were not part ofa modernization exercise which would have involved an embeddeddiagnostic controller, embedded along with the engine and transmission,but was connected to or plugged into a bigger diagnostic system.

It will be appreciated that what is unique about providing the subjectdiagnostic interface unit is that the unit itself is uploaded withdiagnostic knowledge and programming of what is required to be done inorder to perform the diagnostics, for instance for both engines andtransmissions; and then to understand the specific signal measurementrequirements to perform the diagnostic tests on these vehicles.

What is unique to the subject diagnostic interface unit is a combinationof technology that ascertains or knows what one is to measure, thesignal conditions that are to be measured as well as the signalparameters, all in conjunction with diagnostics expertise. This thenpermits the diagnostic interface unit to take advantage of the signalsthat are offered and to make useful diagnostic conclusions.

It is noted that all previous diagnostics were accomplished off boardwith external test equipment. This test equipment had to be plugged intothe legacy connectors and were not embedded or on-board.

It will be appreciated that until the subject invention, no device couldbe hooked up and stay resident and permanently attached to a vehicleconnector so that the processing is in fact resident on board thevehicle to provide the diagnostics, with the results brought out to crewor maintainers at the vehicle.

Thus, the subject system provides simple universal interface diagnosticconclusions similar to those available using older external diagnostictest equipment. Moreover, the subject interface provides a new level ofdiagnostics, more accurate levels of diagnosis and provides informationroll up that is different that which was provided by the old pieces oftest equipment.

It is also important that the subject interface unit permit transmissionof the relevant information to the available crew on the platform ormaintainers at the platform. To this end, the subject diagnosticinterface unit is provided with connectivity to on board computers inthe vehicle, either a mission computer or a dedicated platformdiagnostic computer with or without in-vehicle display. Moreover, thesubject diagnostic interface unit achieves connectivity to new orexisting pieces of test equipment that maintainers that go to thevehicle have available. These include such devices as portablemaintenance aids (PMA) or maintenance support devices (MSDs).

Thus, the subject diagnostic interface unit can be connected to adiagnostic or mission computer that is resident on the vehicle or couldbe connected to an externally-provided portable maintenance aid or amaintenance support device laptop.

In one embodiment the diagnostic interface unit has very specific signalconditioning circuits to address the types of signals that one ismeasuring. This includes the types of voltages that may be required tobe measured, especially by certain types of bridge circuits that aretypically in transducers coupled to the vehicle. In short, thediagnostic interface unit addresses analog-level signals. Thus, thediagnostic interface units are very specific and sensitive to the typeof information that is to be captured. In one embodiment, the diagnosticinterface units also include filter circuits and diode detector circuitsthat perform sampling, signal conditioning and sometimes providediagnostic test stimulus in order to perform the diagnostic testsrequired.

The diagnostic interface unit in one embodiment includes multiplexersfor multiplexing the detected information and amplifiers to amplify thedetected signals to appropriate levels.

Moreover, the diagnostic interface unit is provided withanalog-to-digital conversion circuits that are coupled to a digitalsignal processor, with the powering for the diagnostic interface unitbeing provided by a power supply which often as not is filtered.

The system therefore connects to the dedicated analog connector that hasexisted for perhaps the last 30 years, stays connected in tacticaloperation and provides a device for digitizing the analog signalsavailable from legacy vehicles, and also to provide embedded diagnosticcapabilities where there were none.

In summary, a diagnostic interface unit is provided with intelligenceand is adaptable for servicing not only legacy vehicles with legacydiagnostic connector assemblies, but also is programmable for use withvehicles that have diagnostic capabilities that exceed that provided onthe legacy vehicles.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the subject invention will be betterunderstood in connection with the Detailed Description, in conjunctionwith the Drawings, of which:

FIG. 1 is a diagrammatic illustration of a diagnostic interface unitmade to be resident at a vehicle;

FIG. 2 is a schematic component view of a preferred embodiment of thepresent invention; and

FIG. 3 is a schematic system view of a preferred embodiment of thediagnostic interface unit of the present invention.

DETAILED DESCRIPTION

Referring to FIG. 1, a diagnostic connector assembly in the form of adiagnostic interface unit 10 eliminates the need for special testequipment while providing constant, real time monitoring. Diagnosticinterface unit 10 includes a vehicle connector assembly 12 at one end ofan outer cylindrical housing 14. Housing 14 slips over an innercylindrical housing 16 that is apertured to expose a printed circuitboard assembly 18 having contact pads connected to the connectors ofconnector assembly 12. An RS-422 or like connector 20 is used to connectthe output of board 18 to a diagnostic computer 22.

The diagnostic interface unit approximates a modern engine sensing unit,and is adapted to be permanently installed on vehicles to provideconstant engine status that allows health and status awareness, as wellas, interactive diagnostics and prognostics. The diagnostic interfaceunit provides an analog interface with signal conditioning andswitching, a digitizer with an analog-to-digital converter, a processor,and an industry standard SAE J1939 output at connector 20.

In one embodiment, the diagnostic connector assembly diagnosticinterface unit has the ability to sample, convert and transmit 16signals. Software algorithms, hosted on a portable maintenance aid orsensor interface unit shown representationally by diagnostic computer22, allow interactive diagnostics for dynamic conditions. As will beappreciated, the diagnostic interface unit enables the Condition BasedMaintenance (CBM) desired by the military.

Referring now to FIG. 2, a component view of the subject interface isshown in which among other advantages features a digital signalprocessing chip used with a flash memory.

Here it can be seen that diagnostic interface unit 10 includes adiagnostic connector assembly 30 to which are coupled signalconditioning circuits 32, the outputs of which are coupled to respectivemultiplexers 34 and 36. The multiplexers are coupled to the invertingand non-inverting inputs of an amplifier 38 having its output coupled toa filter 40 and thence to an analog-to-digital converter 42. The outputof the analog-to-digital-converter is coupled to a DSP processor 44. Apower supply and filter 46 has its output applied to the appropriatecircuits requiring filtered power; and the output from DSP processor 44may be either coupled over a transceiver to a bus J1939 bus 48, or CAN,with the processor's output available from the processors' memorysection 50 that may constitute an EEPROM 52, a RAM 54 or a flash driveunit 56.

It is the purpose of the diagnostic interface unit to provide an analoginterface to the analog signals on the vehicle bus and to condition andswitch them utilizing a digitizer coupled to an analog-to-digitalconverter and a processor, with the processor housing the diagnostictools or software to provide a smart interface.

Referring to FIG. 3, the diagnostic interface unit is shown as part of alarger system in which the diagnostic interface unit is one of severaldevices aboard a vehicle. Here diagnostic interface unit 10 is coupledto the analog connector on a vehicle 60, with the output of thediagnostic interface unit being coupled to a J1939 CAN bus, here shownat 62. Also coupled to this bus is a transmission control unit (TCU) 63and an engine control unit ECU or engineering control unit 64.

Bus 62 is coupled to a processing module 70 which may contain either aportable maintenance aid (PMA) or a sensor interface unit (SIU).

In one embodiment a vehicle J1708 bus, is coupled to a central tireinflation system (CTIS) module 74 along with being coupled to anautomatic braking system (ABS) module 76.

Discrete sensors 78 are also coupled directly to a processing module 70.The output of processing module 70 is available on a USB bus 80, a VGAbus 82 to a monitor 84, an RS-422 bus 84 and an Ethernet bus 86, herespecified as a Gig-E x 2 bus. The components shown in FIG. 3 thusconstitute a larger embedded diagnostic system that for instance has aGPS input at 88 and supports an 802.11 link 90.

As can be seen, rather than having all the diagnostics performed byoff-board external test equipment, in the subject invention thediagnostic interface unit permits on-board diagnostics resident on avehicle.

The subject system provides similar diagnostic conclusions to thoseprovided by older external diagnostic test equipment, but in additionprovides new levels of diagnostics, more accurate levels of diagnosticsand information rollup that is different from that available fromexternal pieces of test equipment.

Note, the output of the subject diagnostic interface unit maypotentially either be another computer on-board the vehicle, be it amission computer or a dedicated platform diagnostic computer, or may beinterfaced to external diagnostic equipment.

In either case, the results of the diagnostics are immediately availableto maintainers at the vehicle through displays driven by the diagnosticinterface unit, such as available from portable maintenance aids ormaintenance port devices. Note that the portable maintenance aids ormaintenance support devices are names given to laptops that areavailable to maintainers in the Army or the Marines which are brought upto the vehicles that are in for diagnosis and repair.

It will be appreciated that as shown in FIG. 2 there is very specificsignal conditioning of the signals available at the input to thediagnostic connector assembly. These diagnostic connector assemblies aredesigned with knowledge of the types of signals that one is measuring,the types of voltages that may be required, the types of bridge circuitsthat are typically in transducers and the nature of the analog levels ofsignals that are expected for the particular vehicle.

The RC circuits and diode detectors provide sampling, signalconditioning and sometimes provide stimulus for diagnostic testing ofthe vehicle.

Note that the use of multiplexers enables processing of multiplexed datastreams such that more than one condition can be monitored at one time.The signals can be further conditioned through amplification andfiltering as described above, with the conditioned signals applied to adigital-to-analog converter and then to a digital signal processor intowhich is loaded the diagnostic algorithms employed for monitoring theparticular vehicle or the particular fleet of vehicles.

It is noted that the J1939 vehicle CAN bus is typically available to aidin connecting diagnostic computers or electronic control modules thatprovide control and diagnostics, for instance for an automatic brakesystem or an engine or transmission. Here the J1939 CAN bus provides thedigital backbone that can be dedicated to support control ordiagnostics.

In summary, what is provided for dedicated analog connectors that haveexisted on vehicles for the past 30 years is an interface unit todigitize these signals and provide embedded diagnostic capabilitieswhere heretofore there was none.

While the present invention has been described in connection with thepreferred embodiments of the various figures, it is to be understoodthat other similar embodiments may be used or modifications or additionsmay be made to the described embodiment for performing the same functionof the present invention without deviating therefrom. Therefore, thepresent invention should not be limited to any single embodiment, butrather construed in breadth and scope in accordance with the recitationof the appended claims.

1. A method for providing diagnostic capabilities to legacy vehicleshaving analog connector assemblies that output analog signals relatingto vehicle health, comprising the steps of: attaching a diagnosticinterface unit to the analog connector assembly, the diagnosticinterface unit having specialized signal conditioning circuits and adigital-to-analog converter coupled to a processor; and, providing theprocessor with algorithms to be able to diagnose and prognosticatepresent and future problems relative to the vehicle and to provide anoutput of the diagnosis or prognosis information.
 2. The method of claim1, wherein the signal conditioning circuits include multiplexer circuitsto enable the processor to simultaneously process multiple signals. 3.The method of claim 1, and further including coupling the output of theprocessor to on-board diagnostic equipment.
 4. The method of claim 3,and further including coupling the output of the processor to anoff-board diagnostic computer.
 5. Apparatus for the detecting of signalsavailable from a vehicle for use in diagnosis and prognostication,comprising: an analog connector assembly embedded at said vehicle andadapted to provide signals useful in diagnosis and prognosticationrelated to said vehicle; and, a digital interface unit adapted to beconnected to said analog connector assembly and carrying signalconditioning circuits, filtering circuits, multiplexing circuits, and ananalog-to-digital converter for converting conditioned and multiplexedsignals into digital signals, said digital signals being coupled to aprocessor, said diagnostic interface unit including an output connectorassembly adapted to output signals from said processor to diagnostic orprognosticating computers.
 6. The apparatus of claim 5, wherein saiddiagnostic or prognosticating computers are embedded in said vehicle. 7.The apparatus of claim 5, wherein said diagnostic or prognosticatingcomputers are external to said vehicle.
 8. The apparatus of claim 5,wherein said diagnostic interface unit includes a housing, a diagnosticconnector assembly at one end of said housing adapted to connect to saidanalog connector, a circuit board within said housing carrying at leastsaid processor, and said output connector assembly includes an outputconnector at an end of said housing opposite the end at which saiddiagnostic connector assembly is mounted.
 9. The apparatus of claim 5,wherein said vehicle includes a bus and wherein said diagnosticinterface unit is coupled to said bus.
 10. The apparatus of claim 9,wherein said bus is adapted to be coupled to a processing module. 11.The apparatus of claim 10, wherein said processing module includes oneof a sensor interface unit and a portable maintenance aid.
 12. Theapparatus of claim 9, and further including at least one of a electroniccontrol unit and transmission control unit coupled to said bus.
 13. Theapparatus of claim 10, and further including a vehicle bus coupled tosaid processing module and further including at least one of a centraltire inflation module and automatic braking module coupled to saidvehicle bus.
 14. The apparatus of claim 13, and further including adiscrete sensor coupled to said processing module.
 15. The apparatus ofclaim 10, and further including a GPS receiver coupled to saidprocessing module.
 16. The apparatus of claim 10, and wherein saidprocessing module supports at least one of an 802.11 communicationsnetwork, a USB bus, a VGA bus, an RS-422 bus and a Gig-E x 2 bus.